[Android] Print the stack of deadlocked threads when sharding.

build/android/pylib/utils/reraiser_thread_unittest.py

 # Copyright 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Unittests for reraiser_thread.py."""
 
+import threading
 import unittest
 
 import reraiser_thread
+import watchdog_timer
 
 
 class TestException(Exception):
   pass
 
 
 class TestReraiserThread(unittest.TestCase):
   """Tests for reraiser_thread.ReraiserThread."""
   def testNominal(self):
     result = [None, None]
@@ skipping 48 matching lines @@
 
   def testJoinRaise(self):
     def f():
       raise TestException
     group = reraiser_thread.ReraiserThreadGroup(
       [reraiser_thread.ReraiserThread(f) for _ in xrange(5)])
     group.StartAll()
     with self.assertRaises(TestException):
       group.JoinAll()
 
+  def testJoinTimeout(self):
+    def f():
+      pass
+    event = threading.Event()
+    def g():
+      event.wait()
+    group = reraiser_thread.ReraiserThreadGroup(
+        [reraiser_thread.ReraiserThread(g),
+         reraiser_thread.ReraiserThread(f)])
+    group.StartAll()
+    with self.assertRaises(reraiser_thread.TimeoutError):
+      group.JoinAll(watchdog_timer.WatchdogTimer(0.01))
+    event.set()
+
 
 if __name__ == '__main__':
   unittest.main()